1. Field of the Invention
The present invention relates to a female metal terminal in which when a male metal terminal is fitted into this female metal terminal, a resilient contact piece portion is resiliently contacted with the male metal terminal to guide the same so as to stabilize the contact thereof with the male metal terminal, thereby preventing the increase of a contact resistance so as to stabilize the electrical connection.
The present application is based on Japanese Patent Application No. Hei. 11-171610, which is incorporated herein by reference.
2. Description of the Related Art
FIGS. 4 and 5 show a conventional female metal terminal disclosed in Unexamined Japanese Patent Publication No. Hei. 8-250174.
In FIGS. 4 and 5, the female metal terminal 1 includes a metal terminal body 3 of a box-shape, having an insertion port 2 for inserting a male metal terminal (not shown) therethrough, and a resilient contact piece portion 5 formed by folding that portion of a bottom plate 4 of the metal terminal body 3, extending from an end of the insertion port 2, back into the interior of the metal terminal body 3. The resilient contact piece portion 5 includes a flexing portion 6, bent into the interior of the metal terminal body 3 at the lower side of the end of the insertion port 2, a slanting portion 7 extending obliquely rearwardly from the flexing portion 6 within the metal terminal body 3, and a resilient support portion 8 which extends from a distal end of the slanting portion 7, and is curved toward the bottom plate 4, and is resiliently held against the bottom plate 4.
When the male metal terminal is inserted into the female metal terminal 1, a distal end of the male metal terminal is brought into resilient contact with the slanting portion 7, so that an inserting resistance is produced. When this inserting operation is completed against this inserting resistance, the male metal terminal is held in resilient contact with contact portions 9, formed on an apex portion of the slanting portion 7, thereby securing a predetermined contact load.
A slit 10 is formed in the resilient contact piece portion 5, and extends from the proximal end thereof, connected to the bottom plate 4, toward the distal end thereof in a direction of insertion of the male metal terminal. Each of the flexing portion 6 and the slanting portion 7 is divided by the slit 10 into two sections in the direction of the width of the resilient contact piece portion 5.
The resilient contact piece portion 5 is thus divided into the two sections by the slit 10. With this construction, when the male metal terminal is inserted in inclined relation to the resilient contact piece portion 5, and is brought into contact with the resilient contact piece portion 5 at one side portion thereof, that section of the resilient contact piece portion 5, with which the male metal terminal first comes into contact, is resiliently deformed in a larger amount to undertake a larger proportion of the inserting force of the male metal terminal. Therefore, the inserting resistance can be reduced as compared with a construction in which the inserting force is received by the whole of a resilient contact piece portion of a single plate-like construction.
The resilient contact piece portion 5 is divided into the two sections by the slit 10 as described above, and in this connection, the two contact portions 9, which contact the male metal terminal when the insertion of this male metal terminal is completed, are formed respectively on the apex portions of the two sections of the slanting portion 7. When the insertion of the male metal terminal is completed, the resilient forces of the two sections of the resilient contact piece portion 5 act on the male metal terminal through the respective contact portions 9, and therefore the large contact load can be secured.
In this conventional female metal terminal, when the male metal terminal is inserted into the female metal terminal 1 through the insertion port 2 as shown in FIG. 6, the distal end of the male metal terminal is first brought into contact with the slanting portion 7 of the resilient contact piece portion 5 of the female terminal 1. When the male metal terminal, thus contacted with the slanting portion 7 of the resilient contact piece portion 5, is further inserted, the distal end of the male metal terminal, is guide by the slanting portion 7, and slides over this slanting portion 7 to advance within the female metal terminal 1 while pressing the resilient contact piece portion 5 toward the bottom plate 4. Then, this distal end abuts against the contact portions 9 formed on the apex portion of the slanting portion 7. When the male metal terminal is further inserted, with its distal end thus abutted against the contact portions 9, the distal end of the male metal terminal shaves surface portions of the contact portions 9 or almost the whole of the contact portions 9.
When even the surface portions (part) of the contact portions 9 are thus shaved by the distal end of the male metal terminal, there is encountered a problem that the contact of the contact surfaces of the contact portions 9 becomes unstable, and this unstable contact invites the increase of the contact resistance, so that the electrical connection becomes unstable.